Carotid artery disease is also called carotid artery stenosis. The term refers to the narrowing of the carotid arteries. This narrowing is usually caused by the buildup of fatty substances and cholesterol deposits, called plaque. Carotid artery occlusion refers to complete blockage of the artery. When the carotid arteries are obstructed, you are at an increased risk for a stroke, the third leading cause of death in the U.S.

What Are the Carotid Arteries?

The carotid arteries are two large blood vessels that supply oxygenated blood to the large, front part of the brain. This is where thinking, speech, personality, and sensory and motor functions reside. You can feel your pulse in the carotid arteries on each side of your neck, right below the angle of the jaw line.

How Does Carotid Artery Disease Happen?

Like the arteries that supply blood to the heart -- the coronary arteries -- the carotid arteries can also develop atherosclerosis or “hardening of the arteries” on the inside of the vessels.

Over time, the buildup of fatty substances and cholesterol narrows the carotid arteries. This decreases blood flow to the brain and increases the risk of a stroke.

A stroke -- sometimes called a “brain attack” -- is similar to a heart attack. It occurs when blood flow is cut off from part of the brain. If the lack of blood flow lasts for more than three to six hours, the damage is usually permanent. A stroke can occur if:

The artery becomes extremely narrowed

There’s a rupture in an artery to the brain that has atherosclerosis

A piece of plaque breaks off and travels to the smaller arteries of the brain

A blood clot forms and obstructs a blood vessel

Strokes can occur as a result of other conditions besides carotid artery disease. For example, sudden bleeding in the brain, called intracerebral hemorrhage, can cause a stroke. Other possible causes include:

Sudden bleeding in the spinal fluid space -- subarachnoid hemorrhage

Atrial fibrillation

Cardiomyopathy

High blood pressure

Blockage of tiny arteries inside the brain

What Are the Risk Factors for Carotid Artery Disease?

The risk factors for carotid artery disease are similar to those for other types of heart disease. They include:

Age

Smoking

Hypertension (high blood pressure) -- the most important treatable risk factor for stroke

Abnormal lipids or high cholesterol

Insulin resistance

Diabetes

Obesity

Sedentary lifestyle

Family history of atherosclerosis, either coronary artery disease or carotid artery disease

Men younger than age 75 have a greater risk than women in the same age group. Women have a greater risk than men older than age 75. People who have coronary artery disease have an increased risk of developing carotid artery disease. Typically, the carotid arteries become diseased a few years later than the coronary arteries.